Conversion of hydrocarbon oils



March 14, .1944., o. 1 ROBERTS 2,343,927

CONVERSION OF HYDROCARBON OILS Filed MaICh 1l, 1940 nvnar' scar I L.B01712145 orney Panarea Mer. is, 194s naar? cgoNvnnsioN or nynnocAnoNcias Application March ll, 1940, Serial No. 323,274

'i Claims.

lThe present invention relates to the treatment of hydrocarbons for thepurpose of producing therefrom an improved motor fuel. In its morespecific aspects, the present invention relates to the conversion ofhigher boiling hydrocarbon oils pressure, in the presence of addedquantities of sulfur dioxide (SO2), for -a period of time suiiicient toconvert a substantial proportion of the high boiling oil into. motorfuel of the gasoline boiling range.' The thermal treatment may beeffected at temperatures of from 850 F. to l000 F., and atsuperatmospheric pressures not substantially in excess of about 3000.lbs. per sq. in., and preferably at pressures of the order '.of. 500 to1500 lbs. per sq. in. The cracking reaction 'period may range from 15 to180 secondsv and is preferably of the order of 30 to 60 seconds. Thequantity ci sulfur dioxide employed may vary from 0.1 per cent to 3.0per cent by weight. the preferred amount being from 0.3 per cent to 1.5per cent by weight. Cracking catalysts of the nature oiladsorbentearths, suoli as fullers earth, acid activated clays, bentonite,bauxite, silica gel, and synthetic silicates may be utilized, althoughabout 850 F., the pressure being of the order of 'Z50-ibs. per sq. in.,and the reaction period about 30 seconds. As a result of the thermaltreatment,

the gas oil is decomposed with the production of gasoline hydrocarbons,recycle gas oil, tar, and hydrocarbon gases, the SO2 reacting withcomponents of theoil and assisting in the cracking reaction. Of the SO2originally charged to the system with the gas oil, a substantialproportion, for example, 80 percent to 90 per cent, undergoesdecomposition or reaction, or a combination thereof as the case maybe.with the oil components, the sulfur finally appearing as HzS and theoxygen as water, in the products of the cracking reaction. The crackedproductsv from the furnace coil 5 are introduced into evaporator 8 bymeans of valve-controlled pipe 1, the pressure 'upon the productspreferably being reduced to the order of about 50 lbs. per sq. in. priorto the introduction thereof into the evaporator. In the evaporator.tarry material may be separated from the vaporous cracked products andwithdrawn by means of valve-controlled pipe 9. The vaporous products, i.e., gasoline, recycle gas oil and gases are passed from the evaporatorby means of pipe I0 into a fractionating column II, wherein the gasolineand gases may be separated from the recycle gas oilresulting from thecracking treatment. The recycle gas oil may be withdrawn from thebottomof column II and passed by lmeans of valve-controlled pipe I2 intopipe 3 for recirculation to the cracking furnace coil 5.

such catalysts are not essential to the successful operation of theprocess. The crude products from the cracking operation may be separatedby fractional distillation, whereby there may be recovered a gasolinefraction ofdesired boiling range, tar, recycle gas oil, and gases whichmay be recycled to the conversion process.

My invention may be further understood with' top of fractionating columnII through pipe I3 to condenser IB, wherein the gasoline vapors arecondensed, and the liquid condensate and uncondensed gases are passed bypipe I5 into separator I-G; Inseparator I6 the condensate, i. e.,

gasoline, is separated from the uncondensed gases` and is withdrawntherefrom by means of valvecontrolled pipe Il. This gasoline may thenbe.

treated for theremoval of acid gases such as HzS and SO2 byneutralization with caustic soda solu- 'ltion and water washing.

The uncondensed gases, including HzS, SO2, and gaseous hydrocarbons,Aaccumulating in the upper portion of separator I6, may be ventedthrough valve-controlled pipe I8 or may be re. circulated tothe crackingfurnace coil, by means of valve-controlled pipe I9, pipe 3, and pump 4.Or a portion of the gases may be vented, and the remainder recirculatedas above described.

My invention may be further illustrated by the I following examples,which include runs made in the presence and in the absence of SO2. Inthe examples a gas oil haying a boiling range of 409 F. to 747 F. and anA5 P. I. gravity of 26.8 was subjected to single pass cracking withoutrecyling in the presence and in the absence of SO2, the crackingtemperature being 850 F., the pres-- sure 750 lbs. per sq. in., and thecracking time approximately 30 seconds. The liquid product recoveredfrom the cracking operation was distilled to separate a `gasolinefraction having' a distillation endpoint of 400 F., a gas oil fractionboiling from about 400 F. to 750 F., and tar.

From-the above results, it will be seen that in accordance with myinvention I am able to 'effect a substantial increase in yield ofgasoline of improved anti-knock value, without excessive p drocarbons toa temperature or from 850' F. to

1000 l1i'. and under a substantial superatmospheric pressure, in thepresence of from 0.3 per cent to 3 per cent by weight of sulfur dioxide.and in the absence of water or water vapors introduced from anextraneous source.

4. A process for the conversion of hydrocarbons ot high boiling pointinto those of lower boiling point, which comprises heating saidhydrocarbons to a temperaturelof from 850 F.. to 1000 F.. under asuperatmospheric pressure not substantially in excess of about 3000 lbs.per square inch, in the presence of from 0.3 per cent to 3 per cent byweight of sulfur dioxide, and in the absence oi.' water or water vaporsintroduced from an extraneous source.

5. A process for the conversion of hydrocarbons of high boiling pointinto those of lower boiling point, which comprises heating saidhydrocarbns to a temperature of from 850 I". to

production of tar. While, hereinabove, I have shown theconversion of acracking stock such as gas oil, it is to be understood that my inventionis equally well adapted to the conversion of other high boilinghydrocarbon oils, including crude petroleum, petroleum residuum;asphaltic oils, oils or residues from the hydrogenation orpolymerization of petroleum hydrocarbons, and thelike.

What I claim is: i' 1. A process for the conversion of hydrocarbons ofhigh boiling 'point into those of lower boiling point, which comprisessubjecting said hydrocarbons to cracking conditions of temperature andpressure, in the presence of from 0.3 per cent to 3 per cent by weightof sulfur dioxide, and in the absence of water or water vaporsintroduced from an extraneous source.

2. A process for the conversion of hydrocarbons of high boiling pointinto those of lower boiling point, which comprises heating saidhydrocarbons to a temperature of from 850 F. to 1000* F., in thepresence of from 0.3 per cent to 3 per cent by weight o f sulfurdioxide, and in the absence of water or watervapors introduced v from anextraneous source,

bons of high boiling l'point into those 'of lower 1000" F.. under apressure of from 500 to 1500 lbs. per square inch, in the presence offrom y0.3 per cent to 1.5 percent by weight of sulfur dioxide, and inthe absence of water or water vapors introduced from an extraneousVsource and separating from the resulting conversion products ahydrocarbon fraction of gasoline boiling range. 6. A process for theyconversionof hydrocarboiling point, which comprises heating said hyldrocarbons to a temperature of from 850 F. to

1000 F., in the presence or an incombustible,

solid adsorbent catalystand from 0.3 per cent

